Reengineering biocatalysts: Computational redesign of chondroitinase ABC improves efficacy and stability

Marian H Hettiaratchi; Matthew J O'Meara; Teresa R O'Meara; Andrew J Pickering; Nitzan Letko-Khait; Molly S Shoichet

doi:10.1126/sciadv.abc6378

Reengineering biocatalysts: Computational redesign of chondroitinase ABC improves efficacy and stability

Sci Adv. 2020 Aug 19;6(34):eabc6378. doi: 10.1126/sciadv.abc6378. eCollection 2020 Aug.

Authors

Marian H Hettiaratchi¹, Matthew J O'Meara², Teresa R O'Meara³, Andrew J Pickering¹, Nitzan Letko-Khait¹, Molly S Shoichet^{1

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Affiliations

¹ Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada.
² Department of Computational Medicine and Bioinformatics, University of Michigan, 100 Washtenaw Ave. #2017, Ann Arbor, MI 48109, USA.
³ Department of Microbiology and Immunology, University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, MI 48109 USA.
⁴ Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College St., Toronto, ON M5S 3G9, Canada.
⁵ Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada.

Abstract

Maintaining biocatalyst stability and activity is a critical challenge. Chondroitinase ABC (ChABC) has shown promise in central nervous system (CNS) regeneration, yet its therapeutic utility is severely limited by instability. We computationally reengineered ChABC by introducing 37, 55, and 92 amino acid changes using consensus design and forcefield-based optimization. All mutants were more stable than wild-type ChABC with increased aggregation temperatures between 4° and 8°C. Only ChABC with 37 mutations (ChABC-37) was more active and had a 6.5 times greater half-life than wild-type ChABC, increasing to 106 hours (4.4 days) from only 16.8 hours. ChABC-37, expressed as a fusion protein with Src homology 3 (ChABC-37-SH3), was active for 7 days when released from a hydrogel modified with SH3-binding peptides. This study demonstrates the broad opportunity to improve biocatalysts through computational engineering and sets the stage for future testing of this substantially improved protein in the treatment of debilitating CNS injuries.

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).

Publication types

Research Support, Non-U.S. Gov't